Process for effecting catalytic reactions



J. D. UPHAM PROCESS FOR EFFECTING CATALYTIC REACTIONS Filed April 9,1943 April 24, 1945.

UNREACTED ISOPARAFFIN RECYCLE SLUDG E RECYCLE 4 POROUS LINER REACTIONCHAMBER CATALYST MA KE UP ISOPARAFFI N TOTAL REACTION MIXTURE IINVENTOR.

J. D. UPHAM lax M 7 ATTORNEYS.

Patented Apr. 24, 1945 UNITED STATES PATENT OFFICE PROCESS FOR EFFECTINGCATALYTIC REACTIONS John D. Upham, Bartlesville, kla., assig-nor toPhillips Petroleum Company, a corporation of Delaware Application April9, 1943, Serial No. 482,438 9 Claims. (Cl. 2604834) reactant fluids, orotherwise caused to move through the apparatus, the catalyst utilizedfrequently causes corrosive and/or erosive efiects turbulent flow,operating temperatures, and the like. The corrosive and erosive effectsare particularly noticeable in the presence of solid sus- 'pendedcatalyst utilized in either gaseous or liquid phase reactants, andespecially so where the catalyst itself, the reactants, promotors,and/or products of reaction have a tendency to chemically attack wallsof the reaction vessels and other equipment.

The invention has particular utility in hydrocarbon conversions wheresuch problems are frequently encountered, and a preferred embodiment ofthe invention will be described with with a particular type of catalyst,namely a sludge or slurry of aluminum chloride,

usually promoted with minor amounts of hydrogen chloride. However, itwill be seen that the principles or the invention may be applied toother processes and/or apparatus wherein similar problems are involvedand the necessary modincatibns will readily be made by one skilled inthe art in view of the detailed disclosure herein.

terest at the present time in which these catatom lysts are used, may bementioned isomerizatiomfi of saturated hydrocarbons, and alkylation ofhydrocarbons with alkylating reactants such as oleflns, alcohols, alkylhalides, etc. It has been found that aluminum chloride and like sludge,

which may Or may not contain a free metal hal- 66 P d ide in solution orsuspension, is very corrosive and erosive to most metals and othermaterials of construction, particularly when in motion. Isomerizationand alkylation reactions are now carried out in which such sludge iscirculated or otherwise moved through the apparatus either along with Orcounter-current to reactants, and the corrosion problem has proved to bevery serious. Even in the absence 01' solid material, corrosive eilectsoccur and these are influenced by currents or streams of catalystandreaction mixture being treated, as well as by theinherently corrosivenature of the catalytic materials. It has, in fact, been found that evenwhen such motion is very slow, as for example when a slow dripp ni o1sludge occurs into the bottom 01' a catalyst chamber in which solidaluminum In addition to problems my invention may, in certain inzone,and may also provide a mode or operation in which control o1' reactiontemperatures is readily efl'ectcd.

It is an object of this invention to provide 11mapperatus and processwherein erosion and/or corrosion by moving material is minimized.Another object is to provide apparatus suitable" for effectinghydrocarbon conversions utilizing .a mobile catalyst. A further objectis to provide apparatus particularly suited for alkylation,isomerization, or other processes utilizing catalytically active sludgesor other fluent catalyst ccmpomtions comprising aluminum chloride orother active halides. $till another object is to provide a reaction cberand/or conduit resistant to the corrosive effects of such catalystcompositions. A further object is to provide improvements in so-calledfluid" catalyst systems wherein erosion caused by hard catalystparticles moving through the system is minimized. Yet another object isto provide for the control of temperature, concentration of reactants,and other reaction conditions in catalytic systems of the type describedOther ob jects and advantages of my invention will be apparent from theaccompanying disclosure and discussion.

Briefly, the foregoing purposes and objects of the invention may berealized through a novel construction which permits the substantiallycontinuous maintenance of a protective fluid sheet or film against whichthe corrosive or erosive material in question must impinge. In apreferred form, a reaction chamber, conduit, or other portion of theapparatus comprises an inner perforated or .porous liner, disposedwithin an outer wall, an annular space between the liner and wall beingthus formed. Re'actants and catalyst are introduced into and passedthrough the inner permeable lining in any de-, sired manner,while aportion of the reactants, or recycled product, or diluent material, orany mixture thereof is forced into said annular space ,in a fluidcondition under such a pressure that flow thereof occurs through theperforations or pores into the chamber or conduit carrying the movingcatalyst. Thus a blanket of noncorrosive fluid of little or no catalystcontent is continuously maintained adjacent the inner walls, preventingor restraining contact of erosive or corrosive material with chamberwalls.

It is a feature of my invention that the protec tive fluids sointroduced are relatively non-corrosive and preferably comprise a normalcomponent of the reaction mixture, thus avoiding any unnecessarydilution of products or introduction of extraneous material. However, insome cases, such as those in which a diluent serves other usefulfunctions in the reaction mixture, or in which the character of thereaction mixture is such that a protective film of peculiar propertiesis required, the material used to form said fllm may be one which wouldnormally not be introduced into the process. For example, a gaseousdiluent such as steam may beintroduced through a permeable liner of areaction chamber in a fluid catalytic cracking system to serve the dualfunction of minimizing erosion and supplying heat to the endothermiccracking. As another example, a heavy lubricating oil, soap. grease,wax, or like viscous material may be forced through the inner wall toprovide the protective coating in cases where such viscous material isfound to be required for optimum protection and is innocuous in thesystem. Accordingly by the term "fluid" 1 mean to include viscousmaterials which are flowable through the openings.

In liquid-phase operations I generally prefer to I provide a liquidprotective film in the practice of my invention. However, the film mayupon occasion be gaseous, as when a gas or readily vaporizable liquid isforced throughthe liner and where the construction of the apparatus issuch that a gas film of sumcient continuity may be readily maintained,as for example in vertical conduits or the like. In the case ofgas-phase operations a gas is normally forced through the permeableliner in carrying out the purposes of the invention, although the use ofa liquid in such situation is not precluded and may in fact in someinstances be found desirable.

As an additional feature, the control of temperature in exothermicor'endothermic conver- $10113 may frequently be effected by introductionof suitably cooled or heated fluid into the annular space between outerwall and inner liner, with subsequent flow thereof into the reactionchamber proper. Particularly desirable in the case or exothermicalkyiation and isomerization reactions is the use Of a liquiiiedhydrocarbon material which is normally gaseous at reaction conditions,since a relatively large amount of heat is absorbed through thevaporization of said hydrocarbon and an active, rapidly expendingprotective film of gas is continuously generated on the inner surface ofthe reaction chamber.

In the catalytic reaction of alkylatable hydrocarbons, particularlyparaflins, with olefins it is very important that the concentration ofolefins at all points in the reaction mixture be mamtalned at low value,ordinarily not exceeding 10 mol per cent of the total hydrocarbonspresent at such a point, and frequently being maintained below 1 mol percent. A specific modification of this invention as used in such acatalytic alkylation involves maintainin a rapidly circulatin mixture ofhydrocarbons and fluid alkylation catalyst within a reaction zoneconstructed in accordance with the principles set forth herein, and

introduction of the olefin reactant, preferably mixed with some of thehydrocarbon being alkylated, into the annular space and thence into thereaction chamber, thus providing the desired protective fluid blanketand at the same time a carefully controlled addition of oleflns to thereaction mixture under such conditions that they become rapidlydispersed therein. In this way, optimum ratios of alkylatablehydrocarbon to olefin are readily maintained.

The accompanying drawing shows diagrammatically in partially cut awayview a preferred form of apparatus which may be utilized in carrying outsuch an alkylation process a just described, using ethylene andisobutane as reactants, and the drawing and accompanying descriptionwill further serve to exemplify the invention.

Reaction chamber I0 is made up from an inner perforated liner I1 and another pressure-resistant shell ll. Perforations it are indicateddiagrammatically much largr than the actual size in practice for thesake of clarity in the drawing.

A convenient manner of fabricating such a lining is to first manufacturethe same in the form of an imperforate structure and then to punch ordrill holes of the requisite number and size therein. Of course othermethods of manufacture may be used. A reactant liquid, in this caseisobutane, is introduced to the system through conduit I 8 underpressure, while the aluminum chloride sludge which is used as catalystis introduced through conduit 20. In the modification shown, these twoconduits join in a Venturi-type jet 2| so that the isobutane enters thereaction zone at high velocity carrying with it the catalytic sludge.The jet is passed from settling zone 42 preferably so located anddirected in the reaction chamber that a vigorous agitation andcirculatory motion of the contents thereof is set up and maintained. Ofcourse, agitating and circulating means in addition to or other than Jet2| may be provided, but are generally not so satisfactory, usuallyintroducing mechanical difliculties. The isobutane stream is added at orbelow reaction temperature as required.

Ethylene, either alone or dissolved in other hydrocarbons, enters thesystem through line 22,

is joined via line 24 by some isobutane from line i8, and forced by pump26 through conduit 2| into annular space 30 between jacket I and liner[2 under a pressure substantially higher than that prevailing in thereaction zone. Preferably this stream is at a temperature well belowalkylation temperature and this condition is readily realized in manysystems of low-temperature fractionation is used. Theethylene-containing liquid passes continuously from zone 30 through theperforations l8 and into the interior of reaction chamber I where itforms a substantially continuous fluid film on the inner wall .of linerl2. Ethylene from this film continuously becomes admixed with thecirculating mixture of hydrocarbons and catalyst and reacts with theisobutane to form high yields of six-carbonatom parailins, principallydi-isopropyl. It will be seen that the concentration of free ethylene inthe reaction mixture may readily be maintained at as low a value as isdesired. In the case of more reactive olefins such as isobutylene andthe like, the olefin concentration must be kept even lower than thatused in the system just described, due to the increased tendency of sucholefins to polymerize, and the advantagesof this type of olefin additionwill be readily apparent. The factors of pressure differential acrossperforations 16, size and number of perforation Ii, temperature andviscosity of the ethylene-containing stream, and the various reactionconditions are correlated so as to give the requisite protective effectalong with the proper rate of olefin addition. Introduction of a coldethylene stream in this manner serves not only to remove heat ofreaction, but also to give greater protection due to the maintenance ofliner and pre-reaction of the o efin is minimized. Aluminum chloride isslightly solubl in liquid hydrocarbons, and the'protective fllm providedas described is substantially free from dissolved, as well as suspended,aluminum chloride.

Conduits in the system which carry sludge are constructed of aperforated or porous tube 32 surrounded by an outer tube 34 as will bedescribed. Such conduits are 20, ll, 38, and 4!. A portion of the totalreaction mixture is continuously withdrawn through conduit 36 and passedto settling zone 42 wherein a lower sludge phase II and an upperhydrocarbon phase 48 are separated. Part of the total reaction mixturein conduit 36, may, if desired, be recycled to the chamber via conduitsl8 and 20. Sludge is back to the reaction chamber via conduits 40, 38,and 20. A portion 01' this sludge is usually withdrawn, as by conduit48, to disposal or regeneration, while makeup aluminum chloride isprovided through conduit 49. As shown in the drawing, isobutane fromline i8 is forced by pump 50 through line 52 into annular space 54between porous liner 32 and outer tube 34. When liner 32 is made ofporous ceramic ware while liner i2 is of perforated metal, the pressurein zone ethylene purification wherein.

H at a low temperature,

maintained appreciably higher than the pressure in zone 30. Furthermore,it would be undesirable to introduce any olefin into these conduits.According y, the apparatus is so constructed that the two zones carryingprotective fluid are maintained'separate. In other instances, it may bepreferred that they be continuous. Suflicient isobutane continuouslyforced into the interior of the conduits 20, 36, 38, and to protect thesame against corrosion and erosion caused by sludge moving therethroughby the maintenance of a film 01' liquid isobutane. Thi isobutane, beinga normal component of the reaction mixture, is in no way undesirable,and upon passing into the reaction zone I0 it enters into the alkylationreaction.

of the tube 34, designated by reference numeral II, may itself beperforated or porous to provide protection against corrosion by thecirculating contents oi the reaction chamber. Preferably the Jet is notexposed in the reaction chamber except at its outlet.

Material is passed from in settling unreacted isobutane is separated andrecycled to line ll via conduit 80, while the alkylate is removed fromthe system via line 82.

While the above description has been directed p to a specific apparatussuited particularly to an alkylation process catalyzed by aluminouschloride, the modifications of the apparatus 40 and process so describedwhich are required for substantially prevented.

, pension passed through 8. 54 is generally '75 which adapting the sameto other processes as indicated hereinbefore will readily be supplied byone skilled in the art. As used in the appended claims the termcorrosion and related words refer to corrosion by either chemical actionor mechanical wearing away. as by erosion, or both.

Iclaim:

1. A' method for the conversion of hydrocarbons in the presence of amoving corrosive catalyst which comprises subjecting said hydrocarbonsto conversion conditions in the presence of said moving catalyst withina reaction zone bounded by corrodible permeable walls, and continuopassing into said reaction zone through said permeable walls anon-corrosive fluid which forms a protective fluid barrier between saidwalls and said catalyst, whereby corrosion of said walls is 2. A methodas defined in claim 11 in which said non-corrosive fluid is a normalcomponent of the reaction mixture.

3. A method as defined in claim non-corrosive fluid comprises ahydrocarbons to be converted.

4. A method as defined in claim-1 in portion of said which saidnon-corrosive fiuid further acts to control reaction temperature bydirect heat exchange with the reaction mixture.

5. A method as defined in claim 1 in which finely divided solid crackingcatalyst is suspended in vaporized hydrocarbons and the resultingailssaid reaction zone under cracking conditions.

A process for the comprises synthesis of hydrocarbons passing a streamof alkylatable columns and auxiliary equipment,

1 in which said hydrocarbons through a reaction chamber having permeablewalls, passing a stream of corrosive mobile alkylation catalyst throughsaid reaction chamber in intimate contact with said hydrocarbons,introducing into said reaction chamber through said permeable walls anon-corrosive hydrocarbon fluid comprising olefins, maintainingalkylation conditions within said chamber to effect reaction of saidalkylatable hydrocarbons with said olefins, and introducing said olefinsat such rate so as to avoid undesirably high concentrations of olefinsin the reaction mixture and so as to interpose a relativelycatalyst-free barrier between the catalyst-hydrocarbon mixture and thewalls of the reaction chamber.

'1. A process as defined in claim 6 in which said catalyst comprisesaluminum-chloride, said aikylatable hydrocarbon is isobutane, saidolefin is ethylene, and said fluid comprising olefins serves to removeheat of reaction.

8. In a process wherein a corrosive liquid stream passes through apassageway bounded by a corrodi'ble porous material, the improvement.

which comprises forcing through the pores of said material into saidpassageway a non-corrosive liquid which vaporizes upon the inner surfacethereof, thereby maintaining a substantially continuous expandingprotective film or gas between said surface and said liquid stream.

9. A process for the synthesis of hydrocarbons which comprises passing aliquid stream of isoparafiin through a reaction chamber having permeablewalls, passing a stream of corrosive mobile aluminum chloride alkylationcatalyst through said reaction chamberin intimate contact withhydrocarbons therein, withdrawing from said reaction chamber reactionmixture comprising such catalyst and returning at least a portion ofsowithdrawn catalyst to said reaction chamber through a passagewayhaving permeable walls, introducing into said passageway through saidpermeable walls for flow into said reaction chamber a non-corrosiveolefin-tree liquid comprising isoparamn at such rate so as to interposea relatively catalyst-free barrier between the catalyst and walls,introducing into said reaction chamber through said permeable walls anon-corrosive hydrocarbon fluid comprising olefin and isoparaffin at atemperature below reaction maintaining alkylation conditions within saidchamber to eflect reaction or said isoparaflln with said olefin, andintroducing said fluid comprising olefin and isoparafiln at such rate soas to avoid undesirably high concentrations or olefin in the reactionmixture and so as to interpose a relatively catalyst-free barrierbetween hydrocarbon mixture and the walls or the reaction chamber.

' JOHN D. UPHAM.

temperature,

the catalyst- Disclaimer 2,374,511.John D. Upham, Bartlesville, Okla.PROCESS FOR EFFECTING CATA- LYTIC REACTIONS. Patent dated Apr. 24, 1945.Disclaimer filed Apr. 26, 1948, by the assignee, Phillips PetroleumCompany.

Hereby enters this disclaimer to so much of claims 6 and 7 of saidpatenrb as is

